"Safely" will never mean a 0% crash rate. So, when a failure occurs that causes the vehicle to crash uncontrollably the property damage and casualty level will be determined largely by the vertical density of the vehicles.
> But trucks are less efficient than container ships, and we still use the former when the latter is impossible or too slow
Two issues with this:
a) the cost difference between container ships and trucks is not so large as that of air and ground travel
b) the reason that less efficient trucks are used is exactly because there's an economic demand for delivery and it is the price/time optimal solution.
For someone with a commute that can be shortened from 90 minutes to 15 minutes and makes in excess of $250K a year this is a solution. For everyone else it doesn't make sense.
Computers and elevators aren't comparable analogies, perhaps the jetpack is?
In real world we can't accept this because there are always unpredictable factors, we can only say that probability of a safe flight in a single car is say 99.999%. Then if there are 20 cars one right above another, then probability that none of them crash is only 99.98%, and it could damage all cars below it, so the resulting probability of safe flight in a car reduces to something of order 99.99% instead of 99.999% for a single car. And 99.99% is really not safe enough for everyday flying during many years.
I've been present for 2 highways collisions, avoiding them is super easy. Which is why full lane closures and multi-car pile-ups are as infrequent as they are relative to the frequency of two car accidents.
A vehicle that falls from 100 feet above will be accelerating unlike vehicles in an accident on a highway which will rapidly decelerate.
Furthermore, you now have multiple vehicles taking evasive action based on dynamic predictions that cannot incorporate a collision. The second that one car hits another you're going to lose a chunk of your column from pachinko like bouncing.
Now, instead of a small mechanical failure you can have drastic loss of life because all of the occupants plummeted to their death.
Do you work for Uber?
As I mentioned earlier, the future we are talking about is one with self-driving cars. The fact that the vehicles are accelerating is much less of a concern than sheer number of seconds allowed for an automated system to take evasive maneuvers. (Coordinating evasion is also much easier for automated systems, and traffic collision avoidance systems are widely used in planes, but this is a secondary point https://en.wikipedia.org/wiki/Traffic_collision_avoidance_sy... )
Your anecdotal experience is not really informative. But what is informative are car and plane accident rates, and the fact that altitude separation for planes is already a standard practice for avoiding collisions.
https://en.wikipedia.org/wiki/Separation_(aeronautics)#Verti...
It is a strong contributor to the fact that mid-air collisions are much more rare than the multi-car pile-ups from having cars in adjacent lanes. As I read your logic, you would assert that planes would be better off flying parallel, all at the same altitude, so as to avoid the need for grade separation. But this is not how air traffic is managed. Yes of course planes are able to separate out further horizontally than cars can (and just as a flying car would be able to), and this reduces the risk of collision debris dropping down on top of any other random plane. But this clearly does not mean that if, for whatever reason, planes became more horizontally restricted, they would make less use of vertical space.
Edit: We've hit the end of the reply chain. I see your point about both the opening and closing sentences. Is there any way to say the first one without coming off as hostile? My goal/point was trying to demonstrate how patently wrong the earlier statements were.
The evidence or examples you provide should make that clear. Unless you have very strong irrefutable evidence, I would hesitate making any absolute statement declaring someone wrong. What does it gain you? No one likes to be told outright they're wrong. The goal shouldn't be to score points: it should be to reach common understanding.
If this is something you'd like to cultivate further, you might find the references in my profile useful. I refer to them myself regularly.
From my unsolicited, third-party perspective, two things jump out at me.
- You could do without the first sentence entirely.
- The insinuation that the parent is possibly a shill (an Uber employee)
The rest of it is fairly neutral.
That's the evidence you're giving to dismiss the ability of flying cars to distribute over multiple altitude? Once we've accepted the hypothetical that technology allows for a single car to fly from A to B safely (which is almost certainly automated), it seems clear that having cars move at different altitude will be trivially possible.
> Also, with the advent of KERS and other regenerative systems cars will be able to recapture the bulk of energy consumed for elevation changes. To my knowledge there's no such effective system for planes. So the efficiency on cars is still higher than air vehicles.
No one is disputing that regular cars are more efficient than flying cars. But trucks are less efficient than container ships, and we still use the former when the latter is impossible or too slow. You said "Flying is not a valid commute solution and never will be because of physics", and this just isn't true.